We are requesting a gas chromatograph (GC) mass spectrometer (MS) with quadrupole detector, and flame ionization detector (FID) attached to a second column lodged in the same GC. The system will be completed by a speed-vacuum system for sample preparation. This system will be used for analysis of samples deriving from metabolic studies performed in vivo in humans and animals using stable isotope tracers. Specifically, the GCMS will be mostly used for the determination of the isotopic enrichment of glucose in blood and tissue samples, although we do not exclude that we will use also for glycerol, fatty acid, and amino acid analysis. The expected enrichments (3-10 percent) will be in the optimal detection range of the instrument, which is 0.1-100 percent. The FID will be used for analysis of lipid concentrations and composition pattern in biological samples, such as blood and tissue. The MS detector and the FID can potentially be used in combination if the GC oven program is the same for both type of analysis. The GCMS with FID system will allow us to analyze our samples with a better quality control, faster sample turnover and more direct interaction with the laboratory that measures our samples. This will in turn improve the quality of our research, and reduce the analytical time.